Pyrometer



E. BROWN.

(No Model.)

PYROMETER.

Patented June 5, 1894.

lNVENTOR WITNESSES:

in the head of the pyrometer.

the top plate of the frame which carries the UNITED STATES PATENTOFFICE.

EDWARD BROWN, or PHILADELPHIA, PENNSYLVANIA.

PYRO METER.

SPEGIFICATION- forming part of Letters Patent N0. 520,875, dated. June5, 1894. Application filed September 6, 1 893.", Serial No. 4 4,923- (Nomodel l' Patented in England March 29,1893, No. 8,655.

T0 at? whom it may concern.-

Be it known that I, EDWARD BROWN, a citi -f zen ot: the UnitedjStates,residing at Phila delph1a,inthe county of Philadelphia and State ofPennsylvania, have inventedarnew and. useful Py rometer, of which thefollowing 15 a speeificatiom dated March 29, 1893. 4

perature o'f which -.i s,to.be indicated. I

The ob eot of my invention is, to; censtruct this stem so that it maybeput throughwalle' whichuvary in thickness, or it may be Qim-., mersedina heated fluid, such as melted tin- H which may varyin depth a foot ormore; and

may remain in the said varying medium con--- stantly as a ,fixe'd orstationary pyrometer without changing the accuracy of the indication.'ThiS desirable feature has heretofore been approximated by me, bymakingthe'irrside sliding rod,'which connects the indicatng portion ofthe stem with the mechanism 1n the head, of the same metal as the-inrclosing tube. The result of which is that the pointer indicates higherwith a deeper immersion of the stem. The invention herein describedconsists in the discovery, that as the ratio of expansion of the insidesliding rod is increased above that of the tube inclosing it, thepyrometer becomes more accurate until the excess reaches usually abouttwenty-five .pe'r cent.,-.a'nd in some pyrometer stems thirty per cent.After this point is ascertained a greater ratio of expansion onlydeteriorates it again, gradually, as the ratio is increased. Also in theconstruction of the multiplying gearing within the head of thepyrometer, by which I increase the movement of the pointer and preserveaVery free and regular motion to the pointer. I In the accompanyingdrawings Figure 1 is a vertical section throughthe pyrometerstern. Fig.2 is an elevation showing the mechanism Fig. 3 shows multiplying lever.

Similar letters referto similar parts. In Fig. 1' is shown the stem.This stem has an exterior --tube D of iron or othermetai, closed at thebottom, upon which rests a bar of plumbago-ware E orsome other materialwhich expands'less per degree of heat than the tube D. Upon this bar Erestsa compos- 'ite rod Hconsist-ing oiiiron pieces h and in- Yltermediate pieces of brassorcopper h screwed Olaim-ghas been includedin a patentinjf Great Britain, granted to me, No;' 6,655,, and} tomdriven-hard 'uponthe iron pieces. The ro'd'H is steadied centrallywithin the tube by cililtate therepair of the stem, when the end "isburne'd'ofiibygreat heatgl makethe end of vthick cast iron andscrew itby an inside screw into. the end of thetubeD. By this improvement thepart'of the stem subjected to the i I h I buttons g driven or'screwedupon it. f To fa I My nvention'relates to'the construction of. fixed orstationarypy-rometers which have a long stempro ectinginto a medium,the-ternat K to the tube D. A plug K is screwed destructive action ofheat is easily renewed without the loss of the remaining portion.

his a sliding collar upon the stem.

, Ais a cast iron, box forming the pyrometer head; Thishead is screwedto the stem by' the co'upling M.

.0 is the pointer, 13 the dial. In the case or head A is seen themultiply-- This consists of a frame, N,secured by screws n to the case.f

m is a differential adjusting screw. One

end of it passes through the case, the other i through the frame N. Thescrews it pass through elongated slots in the frame N, and by turningthe screw n a small vertical movement is-given' to the frame N. Withinthe 'frame N is mounted the toothed quadrant P on a pivot, 19. Thespring-S is hooked to an arm of the quadrant P at one end, and to thecase A at the other end. A small pinion n, which carries the pointer 0,gears into the quadrant. At one end of the quadrant P is hinged theadjusting-armW by means of the screw-pin 19 The other end carries a pin,17 .by which it is jointed to the'connecting-link 7". The arm W is alsoslot-ted near to the pin 10*, and a set-screw, p, passes through thesaid slot into the quadrant P and serves to fasten the arm W rigidly tothe quadrantwhenthepin p is at the exact radius required for eachparticular pyrometer. The arm V. isso adjusted that the pyrometerindicates correctly when all the parts of the stem are evenly heated, asconsequent upon its permanent immersion in the medium to be indicated.The other end ing mechanism which-actuates thepointer O.

tom of the tube K.

A pyrometer stem is subject to a variety of uses. Suppose it to be usedin meltedtin up to the point K and it is tested and adjusted accuratefor that immersion, it will, as ordinarily constructed, with the rod Hand tube D of the same material, indicate somewhat higher when immersedup to the collar L. By making the inside rod II of a metal which expandsabout twenty-five per cent. more per degree of heat than the tube D,thesaid proportion varying slightly more or less 1 with the diameteroftherod and tube, I overcome this error. Thisproportion may be adj ustedmore accurately by changingthelcngth of the expanding pieces k until thepointer gives an accurate indication, whatever may be the depth ofimmersion of the stem.

I claim- 1. In apyrometer the combination of mech anism in the head,which is adjusted to indicate' accurately when the stem of the pyrometeris permanently fixed in the heated medium, with an outside expansiontube, an inside bar E, and a sliding rod IL, which rod II as hereindescribed.

isproportioned in its expansion per degree of heat in excess of that ofthe tube inclosing it, up to the vicinity of twenty-five per cent.greater; to maintain accuracy of indication under varying depths ofimmersion as herein described.

2. In a pyrometer stem, the combination of the expansion tube I) and therod I'I made of pieces h, and more expanding pieces h by which the totalexpansion of the rod H is adjusted as and for the purpose hereindescribed.

3. In a pyrometer stem, the combination of the outside tube D, theseparable thick expansion tube K, screw threaded to the tube D, theinterior bar E, the composite sliding rod 4:. In a pyrometer or gagehead, mechanism in combination as followsz-the frame N, pin- .ion n,quadrant P, adjusting arm W, link 0" lever B, connecting link r",substantially as described for multiplying the motion of the link 7'upon the pointer C. l

5. In a pyrometeror gage head the following combination of parts: theframe N the top plate a bent over as shown to form a support for pivotfor the lever B, pinion or, quadrant P, adjusting arm VS, link r,connecting link T for communicating the motion of the stem to thepointer.

EDW. BROWN.

\Vitnesses:

JOHN F. GRANT, LEWIS M. KENSIL.

